1. Field of the Invention
The present invention relates to on-vehicle navigation systems for guiding a vehicle on which route to take and, more specifically, to on-vehicle navigation systems for providing such a route guidance not with a map, but simply using characters and symbols only.
2. Description of the Background Art
On-vehicle navigation systems currently available are broadly classified into two types: one is a multi-function type coming with a high-performance display, combined with television capabilities, capable of displaying characters, graphics, drawings, and others in many colors with high definition; and the other is a type carrying indispensable functions only, and a display coming therewith merely displays characters and symbols simply. With the former type of on-vehicle navigation system, the route guidance provided thereby to an arbitrary destination is driver-friendly, i.e., the driver can easily acknowledge where he/she currently is by a vehicle mark on the displayed map, a recommended route is displayed in a different color, and an enlarged map is displayed at the corresponding intersection. Further, if a traffic jam occurs, relating information is displayed in characters, and the driver also sees a mark indicating the traffic jam at the corresponding location on the map. As such, the multi-function on-vehicle navigation system with a high-performance display can provide the driver with any needed information in an easily perceivable manner.
On the other hand, the latter type of on-vehicle navigation system being popular in the US provides route guidance using no map, but numeric values and arrows to indicate the remaining distance to the destination, the heading direction at the intersection, and the like. In this sense, such guidance is called turn-by-turn guidance.
The turn-by-turn guidance does not require the display to be high in performance, advantageously reducing the cost of the navigation system in a turn-by-turn mode. Moreover, the turn-by-turn display shows minimum information only, consequently the driver glances at the display less often. Such a turn-by-turn on-vehicle navigation system thus does not distract the driver as much as the multi-function on-vehicle navigation system, beneficially leading to safer driving.
As to a difference, in terms of the display screen, between the multi-functional navigation system and the turn-by-turn navigation system, refer to exemplary display screens in xe2x80x9cTurn-by-Turn Displays versus Electronic Maps: An On-the-Road Comparison of Driver Glance Behaviorxe2x80x9d (The University of Michigan Transportation Research Institute, Report No. UMTRI-98-37, January 1999, p. III).
The issue here is that the turn-by-turn display often causes the driver to feel insecure because guidance information provided thereby is kept to a minimum.
To be more specific, the driver often feels insecure about specifying at which intersection a displayed arrow is directing him/her to make a turn, e.g., a right turn. Especially in a case where intersections appear one after another in a close range, e.g., in a downtown area, the distance to the target intersection, if displayed, is not helpful enough. Even if the turn-by-turn display shows intersection names or road names, such name signs are not always posted at the actual intersections. Even after barely specifying the target intersection, if its structure is complicated, e.g., five roads are extending therefrom, and two are respectively directed rightward at 90 and 150 degrees, the driver may again have difficulty in specifying, this time, which road to take. In such a case, even if an arrow showing the corresponding angle is displayed, the driver has a difficulty in deciding which road to take, and continues to feel insecure.
After making a turn at an intersection, or going through an intersection complicated in structure without full confidence, the driver often becomes skeptical about xe2x80x9cWas I supposed to make a turn there?xe2x80x9d or xe2x80x9cAm I on the right track?xe2x80x9d.
If the driver made a wrong turn by mistake, both types of on-vehicle navigation systems notify him/her of the mistake by means of a warning display or sound, automatically find a new route to the destination, or the like. For the driver on the right track, the multi-function navigation system can assure him/her with a vehicle mark displayed on the recommended route. However, the turn-by-turn navigation system offers the driver no assurance of being on the right track, making him/her wonder xe2x80x9cAm I heading in the right direction? No warning yet?xe2x80x9d.
Especially when the driver just needs to keep going straight along the same road for a while, e.g., in a suburb, he/she will be get anxious about xe2x80x9cAm I supposed to keep going this road?xe2x80x9d because no information is to be provided by the turn-by-turn display for the duration of time.
The driver""s anxiety may be increased if the road suddenly looks different, e.g., abruptly becomes narrow, curves 90 degrees, becomes unpaved. In such a case, the driver may wonder xe2x80x9cDid I stray into the wrong road?xe2x80x9d even though he/she is driving properly.
Moreover, the driver will not be free from anxiety after reaching the destination if he/she is new to the area, not knowing what to do and where to go.
That is, when the driver reaches the destination, the map of the area remains displayed if the navigation system is of the multi-function type, and the driver can obtain diverse kinds of information about the area, at least of the displayed range. With the turn-by-turn display, however, the driver will be guided to the destination, but not be provided with information about the area.
Therefore, an object of the present invention is to provide turn-by-turn on-vehicle navigation systems capable of providing drivers with helpful and appropriate information to free them from their various anxieties as discussed above.
The present invention has the following features to attain the object above.
A first aspect of the present invention is directed to an on-vehicle navigation system which provides guidance not with map display, but simply with one or more characters and/or one or more symbols. This system comprises: a data storage section for storing map data; an input section through which a destination is inputted; a position detection section for detecting a current position of a vehicle; a route search section for finding a recommended route from the current position to the destination using the map data; a guidance data generation section for generating, from the map data and the recommended route, guidance data needed for the guidance; a guidance section for providing the guidance in a manner based on the guidance data and the current position; and an output section for making a display output and/or a sound output about the guidance provided by the guidance section. Herein, when the current position of the vehicle is on the recommended route after passing a guidance point, the guidance section provides a message telling that the vehicle is driving properly.
As described above, in the first aspect, the driver is notified of his/her proper turn at the target intersection after completion of the corresponding guidance. Such a notification frees the driver from feelings of anxiety even after making a proper turn at the target intersection, wondering if he/she is on the right track. Notifying the driver in a more clear manner as xe2x80x9cturned properlyxe2x80x9d, the driver can feel relieved to a greater degree.
A second aspect of the present invention is directed to an on-vehicle navigation system which provides guidance not with map display, but simply with one or more characters and/or one or more symbols. This system comprises: a data storage section for storing map data; an input section through which a destination is inputted; a position detection section for detecting a current position of a vehicle; a route search section for finding a recommended route from the current position to the destination using the map data; a guidance data generation section for generating, from the map data and the recommended route, guidance data composed of guidance information needed for the guidance, and area information corresponding to a predetermined point in the vicinity of the recommended route; a guidance section for providing the guidance in a manner based on the guidance data and the current position; and an output section for making a display output and/or a sound output about the guidance provided by the guidance section. Herein, the guidance section provides the guidance according to the area information when the vehicle passes by the predetermined point.
As described above, in the second aspect, the driver can see or hear information about the area in the vicinity of the recommended route on which he/she is driving. This gives the driver assurance of driving on the recommended route, and thus he/she can feel better about driving.
A third aspect of the present invention is directed to an on-vehicle navigation system which provides guidance not with map display, but simply with one or more characters and/or one or more symbols. This system comprises: a data storage section for storing map data; an input section through which a destination is inputted; a position detection section for detecting a current position of a vehicle; a route search section for finding a recommended route from the current position to the destination using the map data; a guidance data generation section for generating, from the map data and the recommended route, guidance data composed of guidance information needed for the guidance, and predetermined destination information about the destination and therearound; a guidance section for providing the guidance in a manner based on the guidance data and the current position; and an output section for making a display output and/or a sound output about the guidance provided by the guidance section. Herein, the guidance section provides the guidance according to the destination information when the vehicle reaches the destination.
As described above, in the third aspect, the driver is provided with information about the destination after reaching it. Such information helps the driver get to know the area easily even if he/she has never been to the area before.
Here, the guidance section in each aspect may provide the message telling that the vehicle is driving properly by referring to a level of satisfaction based on a proximity factor derived from distances from the current position of the vehicle to the recommended route, and to another route closer thereto.
In such a manner, if the message refers to the satisfaction level such as xe2x80x9cturned properly with a satisfaction level of x%xe2x80x9d, the driver himself/herself can judge his/her driving.
In the first aspect, preferably, the guidance data generation section may be so configured as to generate the guidance data including area information corresponding to a predetermined point in the vicinity of the recommended route together with guidance information needed for the guidance, and when the vehicle passes by the predetermined point, the guidance section may be so configured as to further provide the guidance in a manner based on the area information.
Further, in the first aspect, the guidance data generation section maybe so configured as to generate the guidance data including predetermined destination information about the destination and therearound together with guidance information needed for the guidance, and when the vehicle reaches the destination, the guidance section maybe so configured as to further provide the guidance in a manner based on the destination information.
Still further, in the first aspect, the guidance data generation section may be so configured as to generate the guidance data including area information corresponding to the predetermined point in the vicinity of the recommended route, and predetermined destination information about the destination and therearound together with guidance information needed for the guidance, and the guidance section may be so configured as to further provide the guidance in a manner based on the area information when the vehicle passes by the predetermined point, and the guidance in a manner based on the destination information when the vehicle reaches the destination.
With such configurations, the guidance can be provided in a combined manner with the first to third aspects, thereby synergizing the above described effects.
These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.